Private companies control more than four in five care home beds in St Helens, a new report reveals.
The Institute for Public Policy Research think tank, who conducted the research in partnership with charity Future Care Capital, says care standards may slip as for-profit firms carve up the key sector once dominated by local councils.
Their report found that private companies own and run 82% of beds in St Helens's elderly care homes – up from 73% in 2015.
The figure does not include private partnerships or individuals.
In contrast, the voluntary and public sectors provide 9% of beds.
Across England, councils have largely withdrawn from care home provision in recent years amid swingeing Government cuts to funding for social care services.
The research shows private companies rushed to fill this gap.
They now provide 77% of beds in the country, with 88% of councils increasing their use of for-profit care home places over the last four years.
The IPPR has now called on the Government to reassert the state's role in social care by borrowing £7.5 billion to provide an extra 75,000 beds by 2030.
Harry Quilter-Pinner, senior research fellow at the think tank, said: "The social care crisis is about more than just money.
"We need radical reform in who provides care and how they do this.
"Over the last few decades the state has handed over the responsibility for care to the private sector. Too often these firms put profits before people."
The Labour Party has promised state-funded support for over-65s in England who need help with basic tasks like getting out of bed, dressing and washing.
Shadow chancellor John McDonnell set out details of the plan in his speech at the Labour conference in Brighton.
"As the first building block in our new National Care Service the next Labour government will introduce personal care free at the point of use in England," he said.
"Funded not through the Conservatives' gimmicky insurance schemes but, like the NHS and our other essentials, through general taxation."
A Department of Health and Social Care spokeswoman said: "We expect everyone to be able to access high quality, safe and compassionate care – already 84% of providers are rated good or outstanding by the Care Quality Commission.
"People who receive care and their families should be able to have confidence that their care provider has a sustainable future.
"We have given local authorities an additional £1.5bn for social care next year, on top of their existing grants, to continue to stabilise the sector.
"The Prime Minister has said that the Government will set out plans to fix the social care system in due course."